TM 5-3805-258-24-1T R O U B L E S H O O T I N GS T E E R I N G S Y S T E MSTEERING SYSTEM TROUBLESHOOTINGThe 5S5123 Hydraulic Test Group or 5P5224Pressure Gauge Kit is used to make the-pressure testof the steering system. Before any tests are made,visually inspect the complete hydraulic system forleakage of oil and for parts that have damage. Forsome of the tests, a magnet and(either for inches or millimeters)WARNINGa measuring ruleare usable tools.When testing and adjusting the steeringsystem, move the machine to a smooth hori-zontal location. Move away from personnel andmachines that are at work. There must be onlyone operator. Keep all other personnel awayfrom the machine.VISUAL CHECKSA visual inspection of the steering system and itscomponents is the first step when a diagnosis of aproblem is made. Stop the engine and lower theimplements to the ground. To remove the tank fillercap, slowly turn the filler cap until it is loose. If oilcomes out the bleed hole, let the tank pressure lowerbefore the filler cap is removed. Make the inspectionsthat follow:1. Measure the oil level.2. Look for air in the oil that is in the tank. Do thisimmediately after the machine is stopped. Use aclear bottle or container to get a sample of theoil. Look for air bubbles in the oil that is in thebottle.3. Remove the filter elements and look for particlesremoved from the oil by the filter elements. Amagnet will separate ferrous particles from non-ferrous particles (piston rings, O-ring seals,etc.).4. Check all oil lines and connections for damage.PERFORMANCE TESTSPROBLEM: Steering wheel is hard to turn.PROBABLE CAUSE:1.2.3.4.5.6.7.Oil is cold.Restriction in hand metering unit (HMU) pilotlines.Pilot lines to HMU are not connected to properports.Restriction across ball check valve at HMU sup-ply port in steering control valve.Steering pump pressure is low.Bolts are too tight for metering section of HMU.Timing of HMU drive is not correct [pin (1)must align with valley of internal pump gear(2)].T I M I N G O F H M U D R I V E1. Pin. 2. Internal pump gear.PROBLEM: Steering wheel is hard to turn when steeringquickly away from a full turn.PROBABLE CAUSE:1. Not enough clearance between ball check andplug assembly in neutralizer valve.PROBLEM: Steering wheel can be turned when the ma-chine is at full turn.PROBABLE CAUSE:1. Adjustment of striker (stud assembly) for neu-tralizer valve is not correct.2. Seat for the neutralizer ball check has a defect.3. Relief valve opens before striker moves the neu-tralizer valve stem.PROBLEM: Machine does not turn smoothly.PROBABLE CAUSE:1. Flow control valve does not move freely.2. HMU supply line has been installed in field testport (in the steering valve body) instead of itsPerformance tests of the steering system can beused for a diagnosis of poor performance and to findthe source of oil leakage inside the hydraulic system.correct location.4-99